Central to the concept of ecological speciation is the evolution of ecotypes, i.e. groups of individuals occupying different ecological niches. However, the mechanisms behind the first step of separation, the switch of individuals into new niches, are unclear. One long-standing hypothesis, which was proposed for insects but never tested, is that early learning causes new ecological preferences, leading to a switch into a new niche within one generation. Here, we show that a host switch occurred within a parasitoid wasp, which is associated with the ability for early learning and the splitting into separate lineages during speciation. Lariophagus distinguendus consists of two genetically distinct lineages, most likely representing different species. One attacks drugstore beetle larvae (Stegobium paniceum (L.)), which were probably the ancestral host of both lineages. The drugstore beetle lineage has an innate host preference that cannot be altered by experience. In contrast, the second lineage is found on Sitophilus weevils as hosts and changes its preference by early learning. We conclude that a host switch has occurred in the ancestor of the second lineage, which must have been enabled by early learning. Because early learning is widespread in insects, it might have facilitated ecological divergence and associated speciation in this hyperdiverse group.
Tremor is classified into physiological, essential, and parkinsonian tremor by means of clinical criteria. The aim of our work was to extract quantitative features from the measurements of the acceleration of human postural hand tremor. Different mathematical methods were adopted and modified in order to separate these three types of tremor. Best discrimination between physiological and pathological tremors has been achieved by methods distinguishing nonlinear from linear behavior. On the other hand, methods separating different forms of nonlinear behavior have been found to be superior in discriminating parkinsonian and essential tremor. By these methods physiological and pathological tremors can be separated with an error rate below 20% and essential and parkinsonian tremor with an error rate below 10%. This may help to classify tremor time series by objective mathematical criteria and may increase the understanding of the pathophysiological differences underlying these kinds of tremor.
Several strains of the apparently well-known cosmopolitan synanthropic parasitoid of coleopteran stored-product pests, Lariophagusdistinguendus (Förster, 1841) from Western Europe, were studied using DNA sequencing and chromosomal analysis. The presence of at least two cryptic species with different COI sequences and chromosome numbers (n = 5 and 6) was supported. The species with n = 6 is associated with the drugstore beetle Stegobiumpaniceum (Linnaeus, 1758), whereas the other one with n = 5 mostly develops on the granary weevil Sitophilusgranarius (Linnaeus, 1758). A phylogenetic study revealed that the karyotype with n = 6 represents an ancestral character state in this complex. Consequently, the chromosome set with n = 5 which is characteristic of a particular internal clade, apparently originated via chromosomal fusion which was probably preceded by a pericentric inversion. If this is true, inverted chromosome segments could accumulate a number of genetic loci responsible for certain interspecific differences.
We investigate physiological, essential and parkinsonian hand tremor measured by the acceleration of the stretched hand. Methods from the theory of dynamical systems and from stochastics are used. It turns out that the physiological tremor can be described as a linear stochastic process, and that the parkinsonian tremor is nonlinear and deterministic, even chaotic. The essential tremor adopts a middle position, it is nonlinear and stochastic.
In ultrafiltrated plasma (molecular weight less than 50,000) obtained from four patients with multiple muscular trauma and acute post-traumatic renal failure, it was possible to verify a subcomponential specific digestion of the subunits alpha and gamma of phosphorylase kinase isolated from rabbit skeletal muscle. The activity of free proteolytic enzymes in ultrafiltrated plasma as well as an increase of plasma alpha 1-antitrypsin values were correlated with the severity and unfavourable course of the illness. In contrast, the plasma levels of alpha 2-macroglobulin were drastically lowered. The mean total protein concentration in the sera of patients with post-traumatic ARF was lowered, whereas the mean ultrafiltrate protein concentration was significantly enhanced. In ultrafiltrated plasma of two patients with hyperuricaemic ARF, three patients with ARF after drug over-dosage, one patient with acute pancreatic necrosis combined with acute renal failure and one patient with chronic pancreatitis, no proteolytic activity could be detected using phosphorylase kinase as substrate. Studies on the trypsin binding capacity of the plasma protease inhibitors revealed a significantly lowered level in patients with post-traumatic acute renal failure as compared to healthy controls, patients with chronic renal insufficiency and patients on regular dialysis treatment Proteolytic activity was found in ca. 100-fold concentrated diafiltrates (molecular weight greater than 10,000) of patients on regular dialysis treatment. Our data suggest a participation of proteases on protein catabolism in hypercatabolic states. Whilst the blood coagulation system can largely be excluded as a source of proteases, it is possible that proteolytic enzymes may be released from muscle lysosomes and/or macrophages after multiple muscular trauma.
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